This invention relates to the detection of linear and nonlinear distortions in equipment, such as those used in cable and wireless systems, as well as in other applications.
Linear and nonlinear distortions are frequently generated in equipment used in cable systems, and in wireless systems. Thus, nonlinear distortions such as second, third or higher order distortion signals may for example be generated by (overdriven) amplifiers and linear distortions may be caused by multi-path reflections (where reflections accompany the original signal), group delay (where signals at different frequencies travel at different velocities) or amplitude tilt (where signals at different frequencies suffer different attenuations). Excessive distortions affect the image and audio quality experienced by consumers and truck-rolls are typically required in conventional cable and wireless systems to test and identify the source of such distortions and to correct them. Needless to say, such services are expensive. It is therefore desirable to provide techniques that can identify the distortion source without resorting to such expensive methods.